Steatohepatitis in NASH involves a Th1 cytokine response that drives liver injury and elevated levels of proinflammatory cytokines, like TNFα, IL-1β, IL-6, interferon γ (IFNγ) and first apoptosis signal (Fas)-ligand are detected in serum, liver and adipose tissue of humans and mice with NASH phenotype [121]. This evidence concerns the gene IL1B and metabolic dysfunction-associated steatohepatitis.